Capillary Hanger Arrangement for Wellhead Control Line Deployment

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Solution Overview

Problem

Current surface-controlled safety valves for wells are prone to damage and malfunction due to intricate mechanisms and multiple components, making them difficult and costly to manufacture and deploy, and often require working over the well, which is time-consuming and expensive.

Innovation Solution

A capillary string deployment method and apparatus that allows for the installation of a surface-controlled subsurface safety valve using a capillary hanger, which communicates hydraulic fluid with the valve through a capillary string, reducing the need for exposed and complex mechanisms, and enabling deployment without the need to hot-tap wellhead components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a surface controlled safety valve is deployed with intricate mechanisms and multiple components, then the valve can be controlled from the surface, but the valve becomes prone to damage and malfunction

Engineering Contradiction:
Improvevalve reliabilityVSAvoidmechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the complex operating mechanisms (pistons, sleeves, flappers, springs) from the safety valve body, retaining only the essential sealing element. The valve is reduced to a simple cage structure that receives the sealing element, eliminating most moving parts that were prone to damage and malfunction.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The safety valve system is divided into separate functional components: the static cage structure remains in the well, while the sealing element can be independently deployed and retrieved through the capillary string. This segmentation allows the complex control function to be separated from the simple sealing function.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If a surface controlled safety valve is deployed with intricate mechanisms, then the valve can be operated hydraulically, but the manufacturing cost and difficulty increase

Engineering Contradiction:
Improvevalve manufacturing easeVSAvoidmechanism complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent extracts all complex mechanical components from the valve assembly, leaving only a simple cage structure. This dramatically simplifies manufacturing processes, reducing the number of parts that need to be precision-machined, assembled, and tested.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The sealing element is designed as a relatively simple, replaceable component that can be deployed and retrieved multiple times. The simplicity of the cage structure makes the overall system more cost-effective to manufacture compared to traditional valves with complex internal mechanisms.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Productivity

If a safety valve is deployed without working over the well, then deployment time and cost are reduced, but the valve must be deployed through existing tubing constraints

Engineering Contradiction:
Improvedeployment efficiencyVSAvoiddeployment flexibility
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent uses a flexible capillary string to deploy the safety valve components through the existing wellbore and tubing. The capillary string can navigate through curved wellpaths and existing tubing constraints, enabling deployment without working over the well while still reaching the target depth.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The capillary string acts as an intermediary tool that bridges the surface control system and the downhole valve location. It allows hydraulic fluid and control signals to be transmitted through the existing tubing to the valve without requiring direct access to the wellbore.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If exposed mechanisms are used to operate the safety valve, then hydraulic control can be achieved, but the mechanisms become damaged easily

Engineering Contradiction:
Improvemechanism durabilityVSAvoidhydraulic operation capability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent removes all exposed operating mechanisms from the valve assembly. The cage structure has no moving parts that can be damaged by exposure to wellbore conditions. The sealing element is the only component that moves, and it is protected within the cage structure during deployment and operation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces complex mechanical operating mechanisms with a simpler system based on hydraulic pressure applied directly to the sealing element. The capillary string delivers hydraulic fluid that actuates the seal without requiring intermediate mechanical components like pistons, sleeves, or linkages.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The capillary string deployment method simplifies the operation and reduces potential damage to the valve components, providing a more reliable and cost-effective solution for deploying safety valves in wells by using a capillary hanger to convey hydraulic fluid, allowing for efficient operation and retrieval of the safety valve.

Implementation Method 1

a capillary hanger, which communicates hydraulic fluid with the valve through a capillary string

Methodology Applied
Scientific EffectHydraulic fluid conveyance: Hydraulic Press

Data Source

PatentEP2236741B1Capillary hanger arrangement for deploying control line in existing wellhead
Publication Date: 2019.01.02 WEATHERFORD TECHNOLOGY HOLDINGS LLC
  • EP2236741B1 patent drawingFigure 1A~1B
  • EP2236741B1 patent drawingFigure 2A~2B
  • EP2236741B1 patent drawingFigure 3~5B

AI summary

To deploy a capillary string through a wellhead to a downhole safety valve, a control port and a retention port are drilled in an adapter between a casing hanger and a gate valve or elsewhere. The capillary string is connected to a first port of a capillary hanger and installed through the wellhead. The capillary hanger is landed on a tubing hanger, and a side port on the capillary hanger communicates with the control port. Because the side port's location may not align with the control port, operators may need to measure how long the capillary hanger should be. A control line connects to the control port in the wellhead's side to communicate with the capillary line, and a retention rod inserts in the retention port to support the capillary hanger.